64Mb: x32
SDRAM
The SDRAM provides for programmable READ or
WRITE burst lengths of 1, 2, 4, or 8 locations, or the full
page, with a burst terminate option. An auto precharge
function may be enabled to provide a self-timed row
precharge that is initiated at the end of the burst se-
quence.
64Mb (x32) SDRAM PART NUMBER
PART NUMBER
ARCHITECTURE
MT48LC2M32B2TG
2 Meg x 32
The 64Mb SDRAM uses an internal pipelined archi-
tecture to achieve high-speed operation. This archi-
tecture is compatible with the 2n rule of prefetch archi-
tectures, but it also allows the column address to be
changed on every clock cycle to achieve a high-speed,
fully random access. Precharging one bank while ac-
cessing one of the other three banks will hide the
precharge cycles and provide seamless, high-speed,
random-access operation.
The 64Mb SDRAM is designed to operate in 3.3V,
low-power memory systems. An auto refresh mode is
provided, along with a power-saving, power-down
mode. All inputs and outputs are LVTTL-compatible.
SDRAMs offer substantial advances in DRAM oper-
ating performance, including the ability to synchro-
nously burst data at a high data rate with automatic
column-address generation, the ability to interleave
between internal banks to hide precharge time and
the capability to randomly change column addresses
on each clock cycle during a burst access.
GENERALDESCRIPTION
The 64Mb SDRAM is a high-speed CMOS, dynamic
random-access memory containing 67,108,864-bits. It
is internally configured as a quad-bank DRAM with a
synchronous interface (all signals are registered on the
positive edge of the clock signal, CLK). Each of the
16,777,216-bit banks is organized as 2,048 rows by 256
columns by 32 bits.
Read and write accesses to the SDRAM are burst
oriented; accesses start at a selected location and con-
tinue for a programmed number of locations in a pro-
grammed sequence. Accesses begin with the registra-
tion of an ACTIVE command, which is then followed by
a READ or WRITE command. The address bits regis-
tered coincident with the ACTIVE command are used
to select the bank and row to be accessed (BA0, BA1
select the bank, A0-A10 select the row). The address
bits registered coincident with the READ or WRITE com-
mand are used to select the starting column location
for the burst access.
64Mb: x32 SDRAM
64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02
MicronTechnology,Inc.,reservestherighttochangeproductsorspecificationswithoutnotice.
©2002,MicronTechnology,Inc.
2
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